A personal video recorder (PVR) is a generic term for a device that is similar to a videocassette recorder (VCR) but records television data in digital format as opposed to the VCR's analog format. Conventional PVRs encode video data in MPEG-1 or MPEG-2 formats, standards set by Moving Picture Experts Group (MPEG), and store the data in a hard drive. PVRs have all of the same functionality of VCRs (recording, playback, fast forwarding, rewinding, pausing) plus the ability to instantly jump to any part of the program without having to rewind or fast forward the data stream.
A PVR is also referred to as a hard disk recorder (HDR), digital video recorder (DVR), personal video station (PVS), or a personal TV receiver (PTR). Two common PVR systems are TiVo® and ReplayTV®.
A PVR chooses programs based on explicit user requests or some intelligent algorithm that conjectures the user's preferences. The PVR then records the programs onto the hard disk drive. The user has the ability to watch any of the recorded programs at his convenience. The user has the ability to view a program simultaneously while the PVR records another program. Some PVRs even allow another viewer to watch yet another recorded program via network connection.
Unfortunately, one major restriction of a conventional PVR is that only one program can be recorded simultaneously. This restriction comes from the fact that the PVR has only one tuner. It is possible to add more tuners to the PVR. However, doing so significantly increases the cost of the PVR.
Conventional PVR devices are setup to handle the recording of programs in an independent way. If a user wants to record multiple programs, the user must instruct each PVR to record a single program.